What is the Pregnancy Countdown Calculator?
The Pregnancy Countdown Calculator tells you exactly how much time is left until your estimated due date (EDD). Simply enter the due date your doctor or midwife gave you and today's date, and the tool shows the number of days remaining, the equivalent in weeks, and a friendly "weeks and days" breakdown so you always know where you stand on your journey.
How to use it
Enter your estimated due date using the year, month and day fields. Then enter today's date (it defaults to the current date). Press calculate and you'll instantly see your countdown. If the due date has already passed, the days remaining will show as a negative number, which can be handy when you're overdue and waiting.
The formula explained
The math is simple date subtraction. We compute the difference in milliseconds between the two dates and divide by the number of milliseconds in a day (86,400,000) to get whole days:
$$\text{days remaining} = \frac{\text{due date} - \text{today}}{86400000\ \text{ms/day}}$$
To express the countdown in weeks we divide by 7:
$$\text{weeks remaining} = \frac{\text{days remaining}}{7}$$
Worked example
Suppose your due date is December 25, 2025 and today is December 1, 2025. The difference is 24 days. Dividing by 7 gives roughly 3.43 weeks, or 3 weeks and 3 days remaining until baby is due.
$$\frac{24}{7} \approx 3.43\ \text{weeks}$$
FAQ
Is the due date exact? No. A due date is an estimate — only about 4% of babies arrive on the exact day. Most are born within two weeks before or after.
How is the due date calculated? Doctors usually estimate it as 280 days (40 weeks) from the first day of your last menstrual period, or via an early ultrasound.
What if the result is negative? A negative number means the due date has already passed, so you are overdue by that many days.
